1. Field of the Invention
The present invention relates to a method for solar power energy management, and more particularly to a method for solar power energy management with intelligent selection of operating modes taking factors of power supply condition of a solar cell, power consumption of a load and power storage of a rechargeable battery into account.
2. Description of the Related Art
When regular solar cells perform photovoltaic conversion, they easily confront low photovoltaic conversion efficiency and limited power generation dependent upon sunshine intensity. To cope with the above drawbacks, some relevant measures, such as a sun tracking method that automatically keeps a solar cell at its maximum sunshine intensity at all time so as to generate maximum power, are addressed.
Besides being costly, such maximum power tracking method must be applied to an adequate position for mounting. When sunlight intensity turns weak, the photovoltaic conversion system is unable to efficiently utilize the solar energy. The load of the photovoltaic conversion system is constant and needs a stable power supply. Due to insufficient solar energy, the solar cell stops supplying power to the load while other backup power source having sufficient power is switched to supply power for normally operating the load.
If the solar cell does not supply power directly to the load, conventionally, the solar power utilization method first stores power to a rechargeable battery and supplies the power from the rechargeable battery to the load when needed. Such solar power utilization is so inflexible that the generated power fails to be effectively allocated and the resulting solar energy utilization efficiency is low. Currently, solar energy is used only when the sunshine intensity is high. However, solar energy is not effectively utilized when the sunshine intensity is medium or low. In a time of intensifying energy shortage, energy waste must be stopped and an enhanced solar energy utilization needs to be developed.